Elizabeth might not be the main character for the upcoming BioShock Infinite, but the team at Irrational Games wants to make sure that players never have to actually worry about her actions and can focus on controlling DeWitt while the girl tags along.

Ken Levine, the leader of the development studio, tells Eurogamer that, “We knew that was going to be incredibly challenging, but the more we thought about it, either the more excited or the more terrified we got.”

He adds, “There’s not a lot of great AI companions. I really think Alyx was the last one. It’s okay. People are generally okay with it – Skyrim is a great game, but their expectations are fairly low. We knew if we were going to have the player have a voice like we wanted to because we had done so many cyphers, we wanted somebody for him to interact with.”

For Levine, the biggest problem with computer-controlled companions is that they are unable to react to their surrounding environment and the player needs to correct their behavior.

Elizabeth is designed to notice the game world of BioShock Infinite and interact with it, with the team using animation and sounds in order to indicate her personal feelings to the player.

Elizabeth also has unique powers that a gamer can benefit from, but she only uses them when there’s a clear cue in the environment or when she is in clear danger.

Both factions that players will meet on Columbia seek to capture her and use the girl to promote their own interests.

The character has been used to promote BioShock Infinite since it was announced and players have recently reacted angrily to the fact that Booker DeWitt was the focus of the official game cover.

BioShock Infinite will arrive on the PC, the PlayStation 3 and the Xbox 360 in late March 2013.